Application of Connected Morphological Operators to Image Smoothing and Edge Detection of Algae

Connected morphological operators have the virtue of simplifying image while preserving the edge information. Connected morphological operators are used in combination to smooth original algae images which aims to suppress noise and to simplify image. First, area opening is applied to suppress noise and keep the algal body and thin branches which are connected with body. Second, morphological reconstruction from marker and attribute thinning are performed to extract some lost fragments of body contour and acerose spinule. The smoothed algae images preserve the majority of outline information. Thus image smoothing of algae is accompanied with detection of edges simultaneously. Experimental results demonstrate that the composite method proposed in this paper is efficient in noise elimination and edges extracted correspond well with the outlines of algae visually.